Solar power systems offer much promise for clean energy, with few, or zero, carbon emissions. These systems collect incident sunlight and convert this sunlight into a usable form of power, such as heat or electricity. Solar energy offers a clean, inexhaustible, sustainable solution to energy demands and has the potential to supply a very significant fraction of U.S. and global electricity consumption. While the U.S. and global solar power potential is known to be immense, solar power systems have not been economically competitive without government support, to date. Challenges remain to devise solar technologies that can lower installation costs, increase power output, and lower the marginal cost per unit energy produced for a lower levelized cost of energy.
Emerging solar power systems such as concentrating solar power (CSP) systems include falling particle solar receivers that heat particles for energy conversion, energy storage, thermochemical processes, electricity production, and process heating. Present falling particle receivers utilizing gravity to flow particles through the receiver are sensitive to the particle residence time within a concentrated beam of sunlight. Direct absorption solid particle receivers that employ this methodology have the potential to achieve heat-transfer media temperatures of ˜1000° C. However, depending on particle size and external forces that can alter particle flow (e.g., external wind and flow due to convective heat losses); optimized particle flow can be severely affected, which can reduce the receiver efficiency. These previously disclosed processes and systems are not efficient in capturing solar energy to heat particles, which increase costs.
Prior art has utilized screens, porous media, baffling, and louvered obstructions for increased residence time of falling particles. However, issues with thermal-mechanical fatigue, damage/melting from the concentrated solar flux, and increased costs and maintenance present limitations.
The need remains, therefore, for CSP falling particle solar receivers and methods that more efficiently capture solar energy by heating particles for energy conversion, storage, and thermal processes.